English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present the detections of 19 solar flares detected in high-energy gammarays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its firstfour years of operation. Interestingly, all flares are associated with fairlyfast Coronal Mass Ejections (CMEs) and are not all powerful X-ray flares. Wethen describe the detailed temporal, spatial and spectral characteristics ofthe first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7)impulsive flare followed by slowly varying gamma-ray emission over 13 hours,and the 2011 June 7 M2.5 flare, which was followed by gamma-ray emissionlasting for 2 hours. We compare the Fermi-LAT data with X-ray and proton datameasurements from GOES and RHESSI. We argue that a hadronic origin of the gammarays is more likely than a leptonic origin and find that the energy spectrum ofthe proton distribution softens after the 2011 March 7 flare, favoring ascenario with continuous acceleration at the flare site. This work suggeststhat proton acceleration in solar flares is more common than previouslythought, occurring for even modest X-ray flares, and for longer durations.

High-Energy Gamma-Ray Emission From Solar Flares: Summary of Fermi LAT Detections and Analysis of Two M-Class Flares